I did quite a bit of research on flooring. I new it was going to be vinyl but there are quite a few options out there.
Some of them:
1. Sheet vinyl - that's pretty much what I had before, so not an option
2. Vinyl tile you glue down
3. Peel and-stick tiles
The big warning about vinyl tile is that you should not install it on particle board. Because the underlayment (new word I learned) IS particle board and I do not have the skill nor the energy to rip it out and replace it, I decided not to go for vinyl tiles.
I finally found this product:
It is called Allure and it's by Trafficmaster. They claim it's "The Easiest Floor Ever". The advantage is that you don't stick this to the floor. The sections overlap and stick to each other (See the gray bits? They're sticky.) This also makes it pretty waterproof. Important in a bathroom. I wanted to post a link to the Trafficmaster web site but they don't seem to have one. Strange...
I bought the flooring at Home Depot.
About $50 for a 24 square foot box. The bathroom is only 40 square feet so, with tax, $120 total.
Installation was fairly easy, although exhausting. It took me 12 hours to lay the floor. If I was a man with strong muscles it would probably not have taken as long, but cutting through this stuff with a utility knife is an amazing workout!